Expander ring for trawl nets



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EXPANDER RING FOR TRAWL NETS Filed Feb. 18, 1963 5 Sheets-Sheet 5 1 IIIIIHI VENTOR. FRANK zwam BY M 4 r T'O/PA/E 76 United States Patent 3,132,435 EXPANDER RING FOR TRAWL NETS Frank J. Luketa, 5567 Greenwood Ave, Seattle 3, Wash. Filed Feb. 18, 1963, Ser. No. 259,150 9 Illaims. ((31. 43-9) This invention relates generally to the same subject matter as does my copending companion application of the same title, bearing Serial No. 259,154, and filed February 18, 1963.

As is explained in said application Serial No. 259,154, the mesh at the entrance to the codend of a trawl net must be held sufiiciently open that it will not close down to the extent to block entrance of fish. The constriction is due to longitudinal stress upon the meshes, in use, which causes them to close down circumferentially. The solution heretofore proposed has been-to incorporate a rigid expander ring at the entrance to the codend, as disclosed and claimed in my application Serial No. 85,662, filed January 30, 1961. This earlier proposed solution will accomplish the end in view, but it presents a large, bulky mass which cannot readily be wound upon a drum, according to the drum trawling method now. in common use, hence can be used only by trawlers sufiiciently large that the codend can be deposited on deck without winding its entrance about a drum. Few present-day trawlers of United States registry are so large.

The solution proposed by my said companion application, Serial No. 259,154, and herein, is to fix a series of beads to the mesh, so as to define a circle in the vicinity of the entrance to the codend, the afiixation being accomplished while the mesh is relaxed, and being at such close spacings that when the mesh is elongated in use, and so is constricted circumferentially, the beads will come substantially into contact, thereby limiting the constriction and holding open the entrance, the beads mutually supporting one another in a generally circular ring. Nevertheless, when wound upon a drum the circle is collapsed, and the obstruction to winding on the codend largely disappears. When the net is reset the relaxed mesh and the ring again expand.

According to the disclosure of my said companion application Serial No. 259,154, the beads when assembled in operative relation to the mesh are of one-piece formation, although some engaged two points where bars of the mesh crossed. This imposed some restriction on elongation of the mesh at such points. It is the primary object of this invention to form the beads so that they can themselves elongate in such circumstances, and so will impose substantially no restriction to elongation of the mesh, nor stress upon the mesh due to failure of the beads to elongate.

Such elongatable beads are formed of two or more sections, relatively movable. It is a further object to form the sections in such manner that each one will always remain in a given location with respect to a square of the mesh, or to the crossing of two bars of the mesh to which it is secured, regardless of elongation that may vary the distance between the squares or crossings to which other sections of the same bead may be secured.

It is also an object to form the beads in separable but identical halves, and the halves of individual sections likewise identical, whereby they may be molded in a common mold, for economy and simplicity.

With these and other objects in mind, as will appear hereinafter, the present invention relates to elongatable beads exemplified by the forms thereof shown herein, and as described in detail hereinafter.

FIGURE 1 is an isometric view, partly broken away, of a bottom trawl net, typifying the type of net to which the present invention pertains.

FIGURE 2 is a plan view of the meshes in the region 3,132,435 Patented May 12, 1 964 2 of the entrance to the codend, relaxed, and with beads according to this invention applied thereto.

FIGURE 3 is a view similar to FIGURE 2, but with the meshes elongated as they would be in use, and the beads correspondingly elongated.

FIGURE 11 is an isometric view of the modified form I of bead, in process of installation, and FIGURE 12 is a similar view of the bead, fully installed.

FIGURE 13 is a sectional view at the line 13-13 of FIGURE 12, and FIGURE 14 is a sectional View at the line 14-14 of FIGURE 12.

FIGURE 15 is a plan view, partly broken away, of the modified bead applied to the relaxed mesh, and FIG- URE 16 is a plan view of the same with the mesh elongated.

FIGURE 17 is a plan view, similar to FIGURE 15, of the modified bead applied to mesh squares instead of along a bar, and FIGURE 18 is a view of the same with the twine extended.

Referring first to the general view, FIGURE 1, the

net is illustrated as a bottom trawl net, although the invention is applicable also to a midwater trawl net. As shown, it comprises a codend 9 of mesh, a funnel 8 of mesh converging aft and leading to the open entrance to the codend, and curtains 7 diverging forwardly from the upper bosom 81 and joined at to the forward side edges of the funnel. Sweep lines 82 diverge forwardly from the opposite ends of the lower bosom 83 to doors 5 at the opposite sides of and ahead of the net, and curtain lines 70, whereon the curtains hang, diverge forwardly from the opposite ends of the upper bosom to the doors. Towing warps 50 from doors and hence the net forwardly. Suspenders 2 of heavy mesh are located at each side of the funnel. Their after ends are distributed part way about the entrance to the funnel, at the line 98, and their forward ends are gathered to a point. The sweep lines 82 are anchored at such points to the respective suspenders 2, and transmit the drag to the codend through the suspenders. These suspenders tend to constrict circumferentially under longitudinal stress, and this tendency is transmitted to the codend at its entrance.

In essence the present invention is for use with a mesh element which encircles and defines the entrance to the codend, which mesh is so oriented, or is inherently of such twine that it is elongatable under stress, and thereby v is constricted circumferentially. Such mesh element may be the mesh of the codend or of the funnel. Inthe absence of an expander ring or its equivalent the constriction of the mesh might progress until the entrance to the codend is effectively closed, and fish gathered in the funnel could escape. The beads used, in accordance with the basic concept disclosed in my said application, Serial No. 259,154, are themselves elongatable in the forms disclosed herein. Because of their elongation, and the fact that each section is fixed to the mesh at points where mesh bars cross, and spaced from the like points where other sections are fixed, the elongation of the mesh under stress, which would be limited by the beads, is permitted to its full extent in accordance with this present inventhe trawler (not shown) drag the tion, by the accompanying elongation of the beads. Any limitation by the beads on elongation of the mesh would subject the latter to undesirable strains.

The mesh may be elongatable solely because of the orientation of its squares relative to the direction of stress, or alternatively because the twine of which the mesh is made is inherently elastically elongatable, being made for example of nylon, either or both. The elongatable beads according to the present invention in any such event function, to relieve the mesh of undue strain.

It will be understood that the beads are fixed to the mesh, circumferentially around the entrance to the codend, and While the mesh is relaxed, at such close spacings that when the mesh is stressed longitudinally, and so is constricted circumferentially, the heads will substantially contact one another. Each then mutually supports the others, and prevents further closing down of the entrance. Nevertheless, when the mesh is wound upon a drum, the expander ring formed of such beads can collapse and flatten down as it goes over the drum, and can expand again when the net is reset.

The heads 1 are shown in FIGURES 1 and 2. Each is made up of two halves, preferably identical for economy, separable at a diametral plane such as the plane of the mesh. The interior half 1a is disposed Within the mesh of the entrance, and the exterior half 1b outside the mesh. Each bead is elongated in shape, and each is formed of identical forward and rear sections. Each such section is guided in the other section for relative movement in the direction lengthwise of the bead. Each section is fixed to the mesh independently of the fixation of the other section, at points separated in the direction of elongation of the mesh.

The construction of an individual head is best shown in FIGURES 5 and 6. Each half includes identical sections A and B, each of which has a guide post it projecting towards and received within a guide socket 11 of the complemental section. The posts hold the sections in alignment when they are elongated. Each section is also formed with locating means, such as the triangular boss 12 outstanding from the plane of separation of the halves 11a and 11b, and with a triangular socket 13 complemental to and receiving the boss 12 when the halves are assembled with the mesh. The two bosses 12 fit closely within a square of the mesh, as in FIGURE 6, and fix each section A or B and the companion sections of the other halt with relation to its particular mesh square. The halves are held together by headed bolts 14 or the like, passing through holes in one half and threaded into the other half (see FIGURE 4), with one such bolt or more being used with each section.

The beads 1 are applied while the mesh is relaxed, as in FIGURE 2. Their spacing is sufficiently close that when the mesh is elongated, as in FIGURE 3, the consequent circumferential constriction will cause them to come approximately or actually into contact. Thereby they prevent further constriction, and in effect mutually support one another in ring form. Being fixed to the mesh at two squares spaced in the direction of elongation, the sections A and B will separate as the mesh elongates, compare FIGURES 8 and 9. However, the guide posts and sockets 10, i1 permit such separation, while still maintaining the sections in correct relationship, and upon relaxation guide the sections back to their initial positions, as in FIGURE 8.

it will be noted that each half, and each section, is identical with the other half, or the other section. The sections can be molded of rubber, nylon, or other suitable material, all in the same mold.

The beads l as heretofore described have been made of two sections. It is possible to make them of several sections, and a t' 'ee-section bead is shown in FIGURES 10 to 18. The end sections are designated A and B respectively, and the intervening or central section is C.

Each end section is identical, for identical halves of section C are different from the end sections. Each has guide posts It), received within guide sockets 11 in the center section C. Each section is fixed to the mesh, but differing somewhat from the locating means received Within a mesh square, as in FIGURE 8 for instance, the alternative locating means consisting of two bosses 12 for each half of a section, received within two sockets 13, is employed. The four bosses 12' at each location form a pattern that spans both bars of the mesh that cross at a given knot. Two screws, both fastening from the outside, hold the halves together. Each section is thus fixed to the net, independently of other sections, and at points spaced in the direction of elongation.

Upon elongation the end sections A and B each separates from the central section C, to the extent necessary to relieve the mesh from stress. Upon relaxation the guide posts and sockets 11' guide the sections back to their initial positions. The same principle would apply to beads of more than three sections.

As an alternate FIGURES 17 and 18 show a threesectioned bead secured in mesh squares rather than along a bar, similar to FIGURES 5 to 9.

The invention has been shown and described as applied to a bottom trawl net, but would be equally applicable to a rnidwater trawl net.

From the foregoing discussion of several typical embodiments of the present invention, other modifications and adaptations thereof will readily occur to those skilled in the art to which the invention is addressed, within the scope of the following claims.

I claim as my invention:

1. in a trawl net, a mesh element defining the entrance to a codend, and elongatable under stress, to be thereby constricted circumferentiaily, and a plurality of beads fixed to the meshes of said element and distributed about the entrance at sufficiently close spacings to come substantially into contact when the mesh is elongated under normal stress during use, each head being of clongated shape and formed of at least two end sections, means guiding each section for movement longitudinally of the other such section, and means for fixing each individual section to the mesh, at spacings such as will require elongation of the head when the mesh is elongated.

2. A trawl net as in claim 1, wherein each bead is composed of two end sections of substantially identical form.

3. A trawl net as in claim 1, wherein each bead is composed of two end sections of substantially identical form.

4. A trawl net as in claim 1, wherein each head is formed of two halves, separable at a diametral plane, and disposed one half interiorly of and one half exteriorly of the entrance, and wherein the means for fixing each individual section to the mesh includes locating means outstanding from each half of each section, sockets on the complemental halves to receive said locating means, said locating means engaging the mesh to locate each such section, and means to secure together the halves of each section in such location regardless of elongatron of the mesh.

5. A trawl net as in claim 4, wherein each locating means comprises a substantially triangular boss of a size, when combined with the boss of the complemental half, to fill a square of the mesh.

6. A trawl net as in claim 4, wherein each locating means comprises two bosses outstanding from each half at each location, and two sockets in the complemental half for receiving said bosses, the four bosses of the two halves being spaced to straddle both bars of the mesh that cross at each such location, and means to secure together the halves of each section at each location.

7. A trawl net as in claim 4, wherein each head includes two like end sections and at least one intermediate section, the several sections being guided by the guideconomy, and only the ing means for relative movement longitudinally of the bead.

8. A trawl net as in claim 7, wherein each section is formed of two halves, all separable along the common diametral plane, each half of each end section including guide posts projecting towards the intermediate section, and the intermediate section having guide sockets for the reception of said guide posts.

'9. A trawl net as in claim 1, wherein each bead is formed of two halves, sepanable at a diametral plane, and disposed one half interiorly and one half exteriorly of the entrance, and each half includes a half of each section, and wherein the means guiding each lsection for 5 section.

References Cited in the file of this patent UNITED STATES PATENTS Raymond Apr. 4, 1911 Luketa Jan. 30, 1962 FOREIGN PATENTS 294,363 Germany Oct. 4, 1916 

1. IN A TRAWL NET, A MESH ELEMENT DEFINING THE ENTRANCE TO A CODEND, AND ELONGATABLE UNDER STRESS, TO BE THEREBY CONSTRICTED CIRCUMFERENTIALLY, AND A PLURALITY OF BEADS FIXED TO THE MESHES OF SAID ELEMENT AND DISTIBUTED ABOUT THE ENTRANCE AT SUFFICIENTLY CLOSE SPACINGS TO COME SUBSTANTIALLY INTO CONTACT WHEN THE MESH IS ELONGATED UNDER NORMAL STRESS DURING USE, EACH BEAD BEING OF ELONGATED SHAPE AND FORMED OF AT LEAST TWO END SECTIONS, MEANS GUIDING EACH SECTION FOR MOVEMENT LONGITUDINALLY OF THE OTHER SUCH SECTION, AND MEANS FOR FIXING EACH INDIVIDUAL SECTION TO THE MESH, AT SPACINGS SUCH AS WILL REQUIRE ELONGATION OF THE BEAD WHEN THE MESH IS ELONGATED. 